By code, buildings such as industrial, school and public buildings require emergency egress capability. Access openings, such as entranceways, doorways and hallways are often secured by either overhead (vertically traveling) closures or accordion folding (horizontally traveling) closures.
Overhead closures travel within a pair of tracks mounted at opposite sides of the access opening. Segmented panel overhead closures are comprised of hinged panels which pivot relative to one another as they successively shift through an arcuate path as the closure opens and closes. Single panel closures are comprised of a single panel capable of arcuate movement to an open position in which the panel is generally disposed in a horizontal position parallel to the floor upon full opening. Both segmented and single panel overhead closures are usually provided with rollers mounted to the panel(s) which extend laterally from the panel(s) to engage and roll within the tracks.
Overhead coiling closures, also referred to as rolling steel doors, move in a generally vertical path, coiling above the opening as the door is opened. They travel within a pair of tracks positioned on either side of the opening. Rollers are usually not utilized. Because rolling steel doors have many fewer parts than sectional doors, with less risk for damage and inoperability, they make a better solution for facilities that cannot afford opening downtime. For emergency egress applications, downtime, i.e. an inoperable door, can be life threatening.
Accordion folding closures are mounted to an overhead horizontally positioned track.
Regardless of the type of closure, for emergency egress applications any locking mechanism used to secure the closure must automatically release when in an alarm condition regardless of the locking mechanism's power state.
Often times the closures is operated by a powered door operator which also provides locking capability. However, for many applications the locking capability provided by the operator is not sufficient. Consequently it is necessary to provide additional locking to achieve required security.
Accordingly, there is still a continuing need for improved locking assembly designs that will release when in an alarm condition. The present invention fulfills this need and further provides related advantages.